In modern society, mobile terminals are rapidly distributed due to their convenience and necessity. Therefore, service providers and terminal manufacturers provide additional functions in order to further raise utility of the mobile terminal. Recently, as a hardware performance of a mobile terminal and a utility efficiency of a wireless channel are improved, a video telephone function that enables communication with a counterpart user using both a video and a sound is supported. To provide a more efficient video communication service to a user, a function for zooming in/zooming out a camera based on a distance between the camera provided to the mobile terminal and the user may be supported.
As a distance between the camera and the object increases, even when the user zooms in the camera, a mic input gain does not change. In other words, as the distance to the camera increases, a distance between the mobile terminal and a sound source increases, but a user needs to manually adjust a mic input volume in order to compensate for the reduction in the mic input volume caused by the increased distance. However, when the user increases the mic input gain in order to simply receive a voice generated from a far away sound source at a desired volume, neighbor noises increase together. Accordingly, a Signal-to-Noise Ratio (SNR) does not change or even reduce, such that performance deterioration may be caused.
As described above, when a mobile terminal provides a video communication function, as a distance between a user and a microphone of the mobile terminal changes, a size of a sound input to the microphone changes. Therefore, an alternative for improving quality of video communication by minimizing an influence of a noise and increasing an input gain for a voice needs to be provided.